Human Anti-PDGFB Recombinant Antibody (clone MOR8457) (CAT#: PABL-297)

Figure 1 Sensorgrams of binding kinetics of MOR8457 and PDGFRβ-ECD-hIgG1 to different PDGFs.

MOR8457-hIgG1 (A−D), MOR8457- mIgG1 (E−H), or PDGFRβ-ECD-hIgG1 (I−L) were captured by antihuman (A−D, I−L) or antimouse (E−H) IgG antibodies immobilized on CM5 sensor chips. Different concentrations of each PDGF protein (0.25, 0.5, and 1 nM) were injected over the surface with the exception that only 0.5 nM and 1 nm of human PDGF-AB was injected to the surface of MOR8457-hIgG1 (D). The determined binding affinities are listed in Table 3. MOR8457-hIgG1 and MOR8457-mIgG1 showed low pM binding affinities to human, mouse, and rat PDGF-BB, which were comparable with those of PDGFRβ-ECD-hIgG1 binding. MOR8457 bound to PDGF-AB but not PDGF-DD, in contrast, PDGFRβ-ECD-hIgG1 bound to PDGF-DD but not PDGF-AB. MOR8457-hIgG1 (A−D) and MOR8457-mIgG1 (E−H) showed a similar on-rate to each PDGF protein; however, MOR8457- mIgG1 (E−H) showed slower off-rates than MOR8457-hIgG1. The off-rates of MOR8457-mIgG1 were outside the limit of the instrument and estimate the KD to be less than 10 pM.

Kuai, J., Mosyak, L., Brooks, J., Cain, M., Carven, G. J., Ogawa, S.,... & Ponsel, D. (2015). Characterization of binding mode of action of a blocking anti-platelet-derived growth factor (PDGF)-B monoclonal antibody, MOR8457, reveals conformational flexibility and avidity needed for PDGF-BB to bind PDGF receptor-β. Biochemistry, 54(10), 1918-1929.

Figure 2 Concentration-dependent, competitive inhibition of human mesangial cell proliferation by MOR8457-hIgG1.

The effects of increasing concentrations of MOR8457-hIgG1 (0.01, 0.1, 1, and 10 nM) (A) on the concentration response curve of PDGF-BB were tested on human mesangial cell proliferation. Antagonists were mixed with PDGF-BB and incubated for 2.5 h at 25 °C before adding to the cells. Cell proliferation assay was performed as described in Experimental Procedures. Curves shifted to the right with the increased concentration of MOR8457-hIgG1. The extent of the inhibition was surmountable at high concentrations of PDGF-BB, a feature of competitive and reversible inhibition. Schild analysis was performed. Schild regressions of MOR8457-hIgG1 (C) are represented. The average calculated pA2 from two independent experiments was 29 pM for MOR8457-hIgG1 and 55 pM for PDGFRβ-ECD-hIgG1.

Kuai, J., Mosyak, L., Brooks, J., Cain, M., Carven, G. J., Ogawa, S.,... & Ponsel, D. (2015). Characterization of binding mode of action of a blocking anti-platelet-derived growth factor (PDGF)-B monoclonal antibody, MOR8457, reveals conformational flexibility and avidity needed for PDGF-BB to bind PDGF receptor-β. Biochemistry, 54(10), 1918-1929.

Figure 3 Selective targeting of PDGF-B with monoclonal antibody MOR8457 strongly and dose-dependently inhibits biliary fibrosis progression in the Mdr2-/- model.

(A) Experimental design: anti–PDGF-B antibody (MOR8457, IP weekly at 1, 10, and 100 mg/kg) or isotype control mAb (100 mg/kg) was administered for 6 weeks in Mdr2-/- mice of both sexes. Nonselective tyrosine kinase inhibition with imatinib (50 mg/kg/day, oral gavage) was used for comparison. (B) MOR8457 dramatically reduced circulating levels of PDGF-B (serum ELISA). (C) Hepatic collagen content was reduced significantly in Mdr2-/- mice treated with increasing doses of MOR8457. (D) Thickness of periductular onion-skin scarring is reduced dose-dependently in Mdr2-/- mice receiving anti–PDGF-B mAb, but not in the Iso- or imatinib-treated group (Sirius Red, 200×). *Portal vein. (E) Fibrosis-related gene mRNA expression (procollagen α1(I), TIMP-1, and TGFβ2) quantified by quantitative reverse-transcription polymerase chain reaction.

Yoshida, S., Ikenaga, N., Liu, S. B., Peng, Z. W., Chung, J., Sverdlov, D. Y.,... & Schuppan, D. (2014). Extrahepatic platelet-derived growth factor-β, delivered by platelets, promotes activation of hepatic stellate cells and biliary fibrosis in mice. Gastroenterology, 147(6), 1378-1392.

Figure 4 Antibody targeting of PDGF-B achieves robust antifibrotic efficacy in a DDC-feeding model of cholangitis and biliary fibrosis.

MOR8457 mAb (10 and 100 mg/kg/wk) or isotype control antibody (100 mg/kg) were administered IP weekly during fibrosis induction by DDC. (A) Connective tissue staining shows a dose-dependent inhibition of both onion-skin fibrosis (original magnification, 200×) (*portal vein) and (B) a quantitative reduction in collagen deposition (via hydroxyproline) in DDC-fed mice treated with anti–PDGF-B mAb. (C) Decrease in ductular reaction marker (K19, upper panel) is accompanied by a dramatic down-regulation in hepatic stellate cell activation marker α-SMA (middle panel) by Western blot analysis. *P <.05 compared with the isotype control-treated group.

Yoshida, S., Ikenaga, N., Liu, S. B., Peng, Z. W., Chung, J., Sverdlov, D. Y.,... & Schuppan, D. (2014). Extrahepatic platelet-derived growth factor-β, delivered by platelets, promotes activation of hepatic stellate cells and biliary fibrosis in mice. Gastroenterology, 147(6), 1378-1392.